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/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
#include "qpid/framing/SequenceSet.h"
#include "qpid/framing/Buffer.h"
#include "qpid/framing/reply_exceptions.h"
#include "qpid/Msg.h"
using namespace qpid::framing;
using std::max;
using std::min;
namespace qpid {
namespace framing {
namespace {
//each range contains 2 numbers, 4 bytes each
uint16_t RANGE_SIZE = 2 * 4;
int32_t MAX_RANGE = 2147483647;//2^31-1
int32_t gap(const SequenceNumber& a, const SequenceNumber& b)
{
return a < b ? b - a : a - b;
}
bool is_max_range(const SequenceNumber& a, const SequenceNumber& b)
{
return gap(a, b) == MAX_RANGE;
}
}
void SequenceSet::encode(Buffer& buffer) const
{
buffer.putShort(rangesSize() * RANGE_SIZE);
for (RangeIterator i = rangesBegin(); i != rangesEnd(); i++) {
buffer.putLong(i->first().getValue());
buffer.putLong(i->last().getValue());
}
}
void SequenceSet::decode(Buffer& buffer)
{
clear();
uint16_t size = buffer.getShort();
uint16_t count = size / RANGE_SIZE;//number of ranges
if (size % RANGE_SIZE)
throw IllegalArgumentException(QPID_MSG("Invalid size for sequence set: " << size));
for (uint16_t i = 0; i < count; i++) {
SequenceNumber a(buffer.getLong());
SequenceNumber b(buffer.getLong());
if (b < a)
throw IllegalArgumentException(QPID_MSG("Invalid range in sequence set: " << a << " -> " << b));
if (is_max_range(a, b)) {
//RangeSet holds 'half-closed' ranges, where the end is
//one past the 'highest' value in the range. So if the
//range is already the maximum expressable with a 32bit
//sequence number, we can't represent it as a
//'half-closed' range, so we represent it as two ranges.
add(a, b-1);
add(b);
} else {
add(a, b);
}
}
}
uint32_t SequenceSet::encodedSize() const {
return 2 /*size field*/ + (rangesSize() * RANGE_SIZE);
}
bool SequenceSet::contains(const SequenceNumber& s) const {
return RangeSet<SequenceNumber>::contains(s);
}
void SequenceSet::add(const SequenceNumber& s) { *this += s; }
void SequenceSet::add(const SequenceNumber& start, const SequenceNumber& finish) {
*this += Range<SequenceNumber>::makeClosed(std::min(start,finish), std::max(start, finish));
}
void SequenceSet::add(const SequenceSet& set) { *this += set; }
void SequenceSet::remove(const SequenceSet& set) { *this -= set; }
void SequenceSet::remove(const SequenceNumber& start, const SequenceNumber& finish) {
*this -= Range<SequenceNumber>::makeClosed(std::min(start,finish), std::max(start, finish));
}
void SequenceSet::remove(const SequenceNumber& s) { *this -= s; }
struct RangePrinter {
std::ostream& out;
RangePrinter(std::ostream& o) : out(o) {}
void operator()(SequenceNumber i, SequenceNumber j) const {
out << "[" << i.getValue() << "," << j.getValue() << "] ";
}
};
std::ostream& operator<<(std::ostream& o, const SequenceSet& s) {
RangePrinter print(o);
o << "{ ";
s.for_each(print);
return o << "}";
}
}} // namespace qpid::framing
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